Before June 8th, 1978, most black members of the Church had not received the priesthood in this dispensation. While I don't personally believe it was God who instituted that policy in the first place, I most definitely believe God was behind the revelation to end the policy. Because of that, we remember today a true jubilation.
Just over three months later, the First Presidencies' landmark letter was canonized as Official Declaration--2
In the spirit of that jubilation, I want to recommend anew J. Stapley's fantastic sacrament meeting talk: Commemorating the Revelation.